Wood-chipping machine.



EPATENTED JULY 7, 1908.

0. CARR. -WO0D GHIPPING MACHINE.

APPLICATION FILED JULY16, 1906.

8 SHEETSSHEBT 1 No. 892,808. PATENTED JULY 7, 1908. 0. CARR.

WOOD CHIPPING MACHINE.

APPLICATION FILED JULY 16, 1906.

3 SHEETSSHEET 2.

Mfr/ 720632.; na'wzllzr No. 892,808. PATENTED JULY '7, 1908.

O. CARR.

WOOD CHIPPING MACHINE. APPLICATION FILED JULY 16, 1906.

3 SHEETS-SHEET 3.

OMA CARR, OF CANTON, NORTH CAROLINA.

WOOD-CHIPPIN G MACHINE.

Specification of Letters Patent.

Application filed July 1c, 1906. Serial No. 326,434.

Patented July 7, 1908 To all whom it may concern:

Be it known that I, OMA CARR, a citizen of the United States of America,and resident of Canton, county of Haywood, State of North Carolina, haveinvented certain new and useful Improvements in Wood-Chipping Machines,of which the following is a ful and clear specification, reference beinghad to the accompanying drawing, in which- Figure 1 is a plan showingone form of embodiment of my invention; Fig. .2 a side elevation thereofpartly in section; Fig. 3 a

face view of the chip ing disk; Fig. 4 a detail section showing t emanner of mounting one of the knives; Fi 5' a detail section through aportion of t e disk showing the construction and arrangement of theshtters or slashers; Fig. 6 a detail perspective-of the cuttingend ofone of the slitters; Fig. 7 a plan v1ew in detail of the deadplate; Fig.8 demanufacture of paper pulp by the-soda and sulfite processes, t eextraction of tannins, resins, gums, etc., the expulsion of volatileoils, etc. In these operations various degrees of fineness and length offiber are re: quired in the chip'used, the purpose determining the mostsatisfactory form of chip.

. Thus, in the simple extraction of tannins,

colors, gums, etc., and in the winning volatile oilsz where the residualfiber is to have no in ure application other than for fuel, theeffortha's been to divide the fiber ver completely in orderthat themaximum of fiber may be exposed to the extracting solvent, or to thesteam used in expelling the volatiles.- In such industries the wood ischipped across the grain at an angle of about 45, and the chips so madesubjected to further division in some form of defibrator, producingfibers of very ununiform length and much dust.

In the manufacture of paper pulp by the processes above mentioned, theinitial chips are much la er than those just cited, and the degree 0defibration is not carried beyond the point of breaking up the largepieces. Owing to the very high temperaturesand pressures used in makingpulp by the processes referred to, the use of a fine chip is notessential, such necessity arising only when the pulping process is to bepreceded by an extraction process at atmospheric pressure andtemperature not exceeding 212 F.

Recent developments in the manufacture jointly of tanning extract andpaper pulp from tannin bearing woods, indicate the de sirability of achipping mechanism operating, not across the grain of the wood at an ange of 45, but parallel, or nearly parallel with the grain, whereb thewood is divided parallel with the fi er to retain the normal length ofthe same, but thin enough to permit ready penetration by the solventre-- uired for complete removal of the tannins.

his condition of fiber, as essential to the joint manufacture of tanningextract and paer pulp, covered in Letters Patent of the nited StatesSerial No. 762,139, granted to me June 4, 1904. In the practical emloyment of that patent several devices have been worked out to satisfythe condition of fiber required, and ofthese the one herein describedappears to possess exceptional advantages.

I use either a vertical or horizontal disk machine, or a cylindermachine, mounting devices thereon at suchintervals as will give the bestca acity per unit of power a pliedon the disli machines up to 7 0"iameter, six knives, onthe cylinder machines u to 5. 0 diameter, four tofive knives. ese knives I mount by projectin them through the face ofthe disk or cylin er, as the point of a plane projects. Beneath thepoints of the knives slots in the disk or cylinder face permit the chipto pass through and away cm the cutting edge.-

My invention consists in swelling out-the disk or cylinder face at thecentral or middle line of the knife ath slo i back this swell towardsthe side lines of t :inife path to the normal face of the disk orcylinder and providing a deadplate of corresponding shape. On themachines using knives 24" in length and upwards I make this swell about1%, which means 1%" rise half the len th of the knife edge, thedeadplates being s aped to correspond.

To indicate the pglilrpose of this swell of the face c ing the ives,take the case of a flat-face disk chipper with straight knives. Withsuch machines the wood is cut endwise, at an angle-of 45 across thegrain. The pur- .tically impossi le, as the knife pose I accomplish withmy chipper is to greatly reduce this angle of cut, preferably to about8, and to cut the wood sidewise with the grain. If to the ordinar'flat-faced chip per we present a piece or bi et of wood sidewise of thegrain, the knives will take off veneers of a thickness equal to theoutset of the knife, and of a length equal to the length of the billet,and when the billet is consumed to a degree at which the remainingsection is in thickness equal to the clearance between face of machineand deadplate, it will be pulled through. 7 Thus we have, to secure aveneer not exceedin g thick, these requirements: The kn' e must not beset out more than 3- 2 and the clearance between face and dead late thesameclearly pracoint' would strike the deadplate and be knoc ed OK. In

ractice the minimum permissible clearance is, onexceptionally well-builtandrigid machines, not less than %which means that, Working sidewise onthe billet in an ordinary straight-face machine, the final part orsliver ofeach billet will be pulled through thick. If all the precedingveneers from the same billet have been taken off 9;,

prepared material is so variable as to be worthless.

The object of my invention is to provide veneers of constantly uniformthickness, such thickness not to excee and at the same time give aslight shear across the grain to open the fibers. If we present a billetto a swell-faced machine, we find that the .point of the knife entersthe billet first, and keeps in advance of the sides of the knife to theextent of. the swell. The billet is consumed to a stage at which theknife-point has taken ployed, that the clearance between faceanddeadplate may be carried at Now, the right thickness of veneer andabsence of sliver being obtained, there re- 'mains the desirability ofshortening the veneer to a degree at which it becomes more easilyhandled in conveyers. Two methods are available for this purpose. First,b cutt1ng out, or corrugating the knives, as s own 111 Fig. 8, so thatthey present to the wood a number of cuttin points instead of a continuous cutting e ge. So made, the knives are set so that, one followinganother, the

wood is scored out in different paths. If the and the final sliver isdrawnthrough thick, the

however, be applied in such machines.

knives are cut out so that the cutting edges are 2 wide, the veneerswill be cut that width. This method has the disadvantage of losing thecutting capacity of the spaces cut out. Second, as shown in the otherviews, by setting in the face, between the knives, hardened cuttingpoints-or slashers, which precede the knives, cutting out narrow pathsabout deep in the wood, such slashers spaced apart-as the width ofribbon is desired. With the paths so cut, the knife follows and cuts outthe narrowed veneer. In my large machines I space these slashers about 2apart. It is understood that the deadplate or plates must be slotted outto This method I allow the slashers to pass.

to take prefer as it leaves the knife at liberty a full cut at eachstroke.

It is obvious that the arrangement of knives, swell of face, corrugationof knives or provision of slashers, applies to either vertical orhorizontal machines, or to cylinder machines. On the horizontal disk, oron the cylinder machine, multiple feed-boxes may be used. In suchmachines the dead knives must be carried on the housing 01 cover, whichmust be sufficiently heavy and rigid to prevent, vibration. disk machinebut one feed-box is usually employed, being horizontal at rightangles tothe 'disk face, and provided with suitable forced feed, preferably a ramrunning in the feed-box and driven by'a compressed air or steamcylinder. In the horizontal disk and cylinder machines the feed-boxesmay be vertical or on a strong incline, so that the weight of the billetin the box' holds the lower billet against the knives. Forced feed c%n,

asmuch as the vertical disk machine is much In the vertical cheaper tobuild for moderate capacities I 'pomts arranged in one or more radialrows and staggered between the knives.

The letter 11 designates the trough or chute in which the billet issupported as it is forced against the disk by the cross-head e whichlatter is forced forward and retracted by any suitable means. The letterf designates the deadplate fastened at the inner end of the I billettrough or channel.

In Fi 8 the notched knives b hereinbefore exp ained are shown. Havingthus fully described my invention,

bination of a rotary nular an ular swel what I claim and desire tosecure by Letters Patent is I 1. In a wood-chipping machine, thecombination of a rotary member having an annulas swell on its face,knives projecting therethrough and having their cutting edges conformingapproximately to said swell, means for dividing the chips into shortlengths, and means for supporting and feeding the billet.

2. In a wood-chipping machine, the commember having an anon its face,knives projecting t erethrough and having their cutting edges conforminapproximately to said swell, means for divirling the chips into shortlengths, and means for supporting and feeding the billet.

3. In a wood-chipper, the combination of a rotary member having on itsface an annular pro ection or swell and openings through the swell atintervals, knives carried by said member and projecting obliquel throughthe o enings in said annular swel and having t eir cutting edgesconforming to the contour thereof, said openings forming throat-likepassages for the exit of the chips through the rotary member, and meansfor supporting and pressing a billetof wood against said swe ed portionof the rotary member. i 4. In;combination, a rotary member having on itsface a swell having angular sides which meet at the center of the swell,said rotary member having an annular series of openings extendingthrough the swell, knives adjustably secured in said openings and havingtheir cuttin edges extending beyond the angular faces of the swell, saidcutting edges conforming approximately thereto, said openings formingthroat like passages below the ed es of the knives for exit of the chipscutting edge conforming approximately to 1' the contour of the swell,sai openings form ing throat-like passages below .the edges of theknives for exit of the chi s, and means for supporting and feeding aillet of wood against said swelled member.

In testimony whereof I hereunto aflix. my signature in the presence oftwo witnesses this 13th day of July 1906. OMA CARR.

Witnesses:

C. D. DAVIS, L. B. BRIDGES.

portion of the rotary

